“Up six turns!” chorused the hands as they turned the handles, bronze cogs ticking as the teeth interlocked with the thread of the inclination screws. The barrel of the mortar slowly rose, till it was pointing up at the clear sky and was only ten degrees from the vertical.

“Down one quarter turn!”

“Down one quarter turn!”

The barrel came down. Hereward checked the angle once more. All would depend upon this one shot.

“Prime her and ready matches!”

The leading hand primed the touch-hole with fine powder from a flask, while his second walked back along the deck to retrieve two linstocks, long poles that held burning lengths of match cord.

“Stand ready!”

Hereward took one linstock and the leading gunner the other. The rest of the gun crew walked aft, away from the mortar, increasing their chances of survival should there be some flaw in weapon or bomb that resulted in early detonation.

“One for the sea, two for the shore, three for the match,” Hereward chanted. On three he lit the bomb’s fuse and strode quickly away, still chanting, “four for the gunner and five for the bore!”

On “bore” the gunner lit the touch-hole.

Hereward already had his eyes screwed shut and was crouched on the deck fifteen feet from the mortar, with his back to it and a good handhold. Even so, the flash went through his eyelids and the concussion and thunderous report that followed sent him sprawling across the deck. The Strongarm pitched and rolled too, so that he was in some danger of going over the side, till he found another handhold.

Hauling himself upright, Hereward looked up to make sure the bomb had cleared the rim of the gorge, though he knew that if it hadn’t there would already be broken rock falling all around. Blinking against the spots and luminous blurring that were the after-effects of the flash, he stared up at the sky and a few seconds later, was rewarded by the sight of another, even brighter flash and, hard on its heels, a deep, thunderous rumble.